/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2005 INRIA, France Telecom
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */
package salve.asmlib;

import java.util.HashMap;
import java.util.Map;

/**
 * A named method descriptor.
 * 
 * @author Juozas Baliuka
 * @author Chris Nokleberg
 * @author Eric Bruneton
 */
@SuppressWarnings("unchecked")
public class Method {

	/**
	 * Maps primitive Java type names to their descriptors.
	 */
	private final static Map DESCRIPTORS;

	/**
	 * The method name.
	 */
	private final String name;

	/**
	 * The method descriptor.
	 */
	private final String desc;

	static {
		DESCRIPTORS = new HashMap();
		DESCRIPTORS.put("void", "V");
		DESCRIPTORS.put("byte", "B");
		DESCRIPTORS.put("char", "C");
		DESCRIPTORS.put("double", "D");
		DESCRIPTORS.put("float", "F");
		DESCRIPTORS.put("int", "I");
		DESCRIPTORS.put("long", "J");
		DESCRIPTORS.put("short", "S");
		DESCRIPTORS.put("boolean", "Z");
	}

	/**
	 * Creates a new {@link Method}.
	 * 
	 * @param name
	 *            the method's name.
	 * @param desc
	 *            the method's descriptor.
	 */
	public Method(final String name, final String desc) {
		this.name = name;
		this.desc = desc;
	}

	/**
	 * Creates a new {@link Method}.
	 * 
	 * @param name
	 *            the method's name.
	 * @param returnType
	 *            the method's return type.
	 * @param argumentTypes
	 *            the method's argument types.
	 */
	public Method(final String name, final Type returnType, final Type[] argumentTypes) {
		this(name, Type.getMethodDescriptor(returnType, argumentTypes));
	}

	@Override
	public boolean equals(final Object o) {
		if (!(o instanceof Method)) {
			return false;
		}
		Method other = (Method) o;
		return name.equals(other.name) && desc.equals(other.desc);
	}

	/**
	 * Returns the argument types of the method described by this object.
	 * 
	 * @return the argument types of the method described by this object.
	 */
	public Type[] getArgumentTypes() {
		return Type.getArgumentTypes(desc);
	}

	/**
	 * Returns the descriptor of the method described by this object.
	 * 
	 * @return the descriptor of the method described by this object.
	 */
	public String getDescriptor() {
		return desc;
	}

	/**
	 * Returns the name of the method described by this object.
	 * 
	 * @return the name of the method described by this object.
	 */
	public String getName() {
		return name;
	}

	/**
	 * Returns the return type of the method described by this object.
	 * 
	 * @return the return type of the method described by this object.
	 */
	public Type getReturnType() {
		return Type.getReturnType(desc);
	}

	@Override
	public int hashCode() {
		return name.hashCode() ^ desc.hashCode();
	}

	@Override
	public String toString() {
		return name + desc;
	}

	/**
	 * Returns a {@link Method} corresponding to the given Java method
	 * declaration.
	 * 
	 * @param method
	 *            a Java method declaration, without argument names, of the form
	 *            "returnType name (argumentType1, ... argumentTypeN)", where
	 *            the types are in plain Java (e.g. "int", "float",
	 *            "java.util.List", ...). Classes of the java.lang package can
	 *            be specified by their unqualified name; all other classes
	 *            names must be fully qualified.
	 * @return a {@link Method} corresponding to the given Java method
	 *         declaration.
	 * @throws IllegalArgumentException
	 *             if <code>method</code> could not get parsed.
	 */
	public static Method getMethod(final String method) throws IllegalArgumentException {
		return getMethod(method, false);
	}

	/**
	 * Returns a {@link Method} corresponding to the given Java method
	 * declaration.
	 * 
	 * @param method
	 *            a Java method declaration, without argument names, of the form
	 *            "returnType name (argumentType1, ... argumentTypeN)", where
	 *            the types are in plain Java (e.g. "int", "float",
	 *            "java.util.List", ...). Classes of the java.lang package may
	 *            be specified by their unqualified name, depending on the
	 *            defaultPackage argument; all other classes names must be fully
	 *            qualified.
	 * @param defaultPackage
	 *            true if unqualified class names belong to the default package,
	 *            or false if they correspond to java.lang classes. For instance
	 *            "Object" means "Object" if this option is true, or
	 *            "java.lang.Object" otherwise.
	 * @return a {@link Method} corresponding to the given Java method
	 *         declaration.
	 * @throws IllegalArgumentException
	 *             if <code>method</code> could not get parsed.
	 */
	public static Method getMethod(final String method, final boolean defaultPackage) throws IllegalArgumentException {
		int space = method.indexOf(' ');
		int start = method.indexOf('(', space) + 1;
		int end = method.indexOf(')', start);
		if (space == -1 || start == -1 || end == -1) {
			throw new IllegalArgumentException();
		}
		// TODO: Check validity of returnType, methodName and arguments.
		String returnType = method.substring(0, space);
		String methodName = method.substring(space + 1, start - 1).trim();
		StringBuffer sb = new StringBuffer();
		sb.append('(');
		int p;
		do {
			String s;
			p = method.indexOf(',', start);
			if (p == -1) {
				s = map(method.substring(start, end).trim(), defaultPackage);
			} else {
				s = map(method.substring(start, p).trim(), defaultPackage);
				start = p + 1;
			}
			sb.append(s);
		} while (p != -1);
		sb.append(')');
		sb.append(map(returnType, defaultPackage));
		return new Method(methodName, sb.toString());
	}

	private static String map(final String type, final boolean defaultPackage) {
		if (type.equals("")) {
			return type;
		}

		StringBuffer sb = new StringBuffer();
		int index = 0;
		while ((index = type.indexOf("[]", index) + 1) > 0) {
			sb.append('[');
		}

		String t = type.substring(0, type.length() - sb.length() * 2);
		String desc = (String) DESCRIPTORS.get(t);
		if (desc != null) {
			sb.append(desc);
		} else {
			sb.append('L');
			if (t.indexOf('.') < 0) {
				if (!defaultPackage) {
					sb.append("java/lang/");
				}
				sb.append(t);
			} else {
				sb.append(t.replace('.', '/'));
			}
			sb.append(';');
		}
		return sb.toString();
	}
}